In the related art, there are two types of four-section headphones. For one type, the pins of the headphone plug are arranged in a sequence of an audio channel output pin (a left-channel and a right-channel), a microphone pin and a ground pin. For the other type, the pins of the headphone plug are arranged in a sequence of a channel output pin (a left-channel and a right-channel), a ground pin and a microphone pin. For the headphone plug of a three-section headphone, a channel output pin is a single-channel, and a sequence of a microphone pin and a ground pin is also divided into the above two types. The sequence of the microphone pin and the ground pin in the audio plug is different, which may cause a mismatch between different types of audio plugs and the sockets disposed in electronic apparatus. At present, there is neither professional detecting device which is capable of distinguishing the type of the audio plug, nor audio plug detectable by the detecting device to distinguish the type of the audio plug.